NORTH LAS VEGAS, Nev. — A southern Nevada gun dealer wants to auction a handgun once owned by a rogue former LAPD officer who killed four people and fatally shot himself during a manhunt in February.

George Bramlett, owner of Bargain Pawn, said he plans to donate the money to the families of two California police officers Dorner killed. But administrators handling the funds for San Bernardino County Sheriff Deputy Jeremiah MacKay and Riverside police Officer Michael Crain say the families don't want the money.

Bramlett posted the gun for auction Tuesday on a website, gunbroker.com, along with images of the sales receipt listing Dorner's date of birth, California driver's license number and La Palma, Calif., address. Bramlett bought the .38 special revolver from Dorner in January for $50.

By today, the bidding was approaching $500 for a gun that Bramlett said might otherwise be worth $300. Bramlett said he thought it might fetch thousands before bidding ends April 23.

"We're trying to do the right thing," Bramlett said. "Every cent that we get will go to the two police families. They both had kids."

The administrators of the funds benefiting the two slain officers said today they don't want money tainted by any association with Dorner, who went on a killing rampage to avenge people he said ended his law enforcement career.

Riverside police Sgt. Brian Smith, president of the Riverside Police Officers Association, called the effort "morbid."

"I appreciate what he's trying to do. And we don't like to turn money down," Smith said. "But when you get right down to it, Jeremy and Mike were murdered by this animal. We wouldn't want to do that to the family members."

The San Bernardino Sheriff's Employee Assistance Team "would not knowingly accept a donation to the MacKay family which was in any way associated with the suspect," Cindy Bachman, a sheriff's office spokeswoman, said in an email.

Dorner, 33, had a home in Las Vegas where he kept several guns around the house, according to a manicurist who rented a room from him in the summer of 2008.

"On the floor, under the cushions. When I would clean, I would find guns," J'Anna Viskoc said in a February interview with The Associated Press.

Bramlett, a licensed federal firearms dealer who has been in business since 1986, said Dorner was an occasional customer.